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Abstract

Introduction: Left ventricular hypertrophy (LVH), the most common cardiac consequence of hypertension, is an independent strong risk factor for cardiovascular mortality and morbidity. LVH is associated with hypertrophy of cardiac myocytes as well as extracellular matrix remodeling, which may reduce myocardial blood volume (MBV) estimated by using myocardial contrast echocardiography (MCE) with the compensation for acoustic field inhomogeneity. Angiotensin II receptor blocker (ARB) has been shown to regress LVH in hypertensive patients. We thus determined whether MBV is reduced in hypertensive patients and ARB could regress LVH and improve MBV.

Methods: In 12 hypertensive patients (HT, 58±15 years) with echocardiographically diagnosed LVH and 10 normal control subjects (52±13 years), echocardiography and MCE with continuous infusion of Levovist were performed. Apical 4-chamber views of intermittent harmonic power Doppler imaging were acquired at end-diastole of every sixth beat. MBV was calculated as 10x/10×100%, where X was myocardial contrast intensity minus contrast intensity of the adjacent intracavity blood pool in dB. Eight patients in HT group received ARB, valsartan (80–160 mg/day) for 6 months and echocardiography and MCE were repeated.

Results: Baseline mean blood pressure (mBP) and left ventricular mass index (LVMI) were higher in HT than in control subjects (mBP: 107±14 vs 95±13 mmHg, p<0.05; LVMI: 143±38 vs 94±15 g/m2, p<0.01). LV ejection fraction did not differ between groups. MBV was significantly lower in HT than in control subjects (2.55±0.37 vs 3.31±0.61%, p<0.01). MBV did not correlate with mBP, but inversely correlated with LVMI (r=−0.61, p<0.01). After 6 months of treatment of hypertension by valsartan, mBP and LVMI significantly decreased (mBP: 110±17 to 94±13 mmHg, p<0.05; LVMI: 153±44 to 129±24 g/m2, p<0.05), and MBV significantly increased (2.41±0.36 to 2.63±0.26%, p<0.05). A significant correlation was seen between change in MBV and LVMI (r=−0.74, p<0.05), but not mBP.

Conclusions: MBV was reduced in hypertensive patients with LVH. The ARB valsartan could increase MBV, which was associated with the regression of LVH.